1. Field of the Invention
The present invention is related to railway rails and, more particularly, is directed towards a new and improved clip for fastening a railway rail to its underlying support.
2. Description of the Prior Art
Many systems have been suggested for directly fastening railway rails to their underlying support structures. With the advent and ever-increasing popularity of modern subway rail systems, the deficiencies of presently utilized rail fastening systems become increasingly apparent, as does the need for a new and improved system to overcome such deficiencies.
One of the more widely utilized rail fastening systems employs a rail clip in the form of a spring steel rod, usually of circular cross-section, which has a first end anchored in an elongated tubular shoulder positioned adjacent the rail. From this end, the rail clip is bent in a convoluted fashion so as to bear against and thereby secure the lower flange of the rail against its underlying support. The clip terminates in an elongated end substantially parallel to the first end and which rests adjacent the tubular shoulder. The clip is installed by longitudinally inserting the first end into the tubular shoulder until the convoluted portion bears properly against the flange. Insulators, spacers, resilient pads and other equipment may be utilized as necessary to provide the desired resiliency, electrical isolation, and the like. Rail clips of this nature are manufactured, for example, by Pandrol Limited of London, England, while a typical fastening and underlying support system therefor is manufactured by, for example, Landis Rail Fastening Systems, Inc. of Los Altos, California.
One problem with the Pandrol type of clip described above has been that, after installation, it provides insufficient resistance to longitudinal movement such that the clips are relatively easy prey for removal by vandals. While their transverse movement (i.e., movement transverse to the axis of the rail) is limited by the anchoring tubular shoulder, there is no similar structure to limit their longitudinal movement (i.e., movement parallel to the rail axis). A person desiring to remove such a clip need only apply sufficient force in a longitudinal direction to remove the first end from the tubular shoulder.
Such a low resistance to longitudinally applied forces presents a potentially hazardous situation in that a loose wheel on the train, or other protrusion from a rail car, could easily dislodge a clip upon impact, thereby loosening the rail and creating a substantial safety hazard.
Additionally, a train moving over the rail imparts a standing wave thereto such that, over a period of time, the vibrational forces resulting from repeated standing waves tend to loosen the clips from their supports, thereby creating another hazard.
A further disadvantage with respect to the prior art rail clips described above is that it is difficult for a workman to judge when the clip is properly fully inserted into its support. There is no positive means for locking same in its fully installed position.
Prior art patents in this general area of which I am aware include: U.S. Pat. Nos. 1,109,001; 2,816,715; 3,558,050; 3,576,293; 3,658,246; 3,784,097; 3,910,493; and British No. 832,872.